双链式悬索桥地震反应特征研究

双链式悬索桥采用钢加劲梁和钢筋混凝上索塔，使得阻尼在全桥中呈非经典阻尼耗能特性，导致主坐标系中的运动方程耦联。基于复阻尼理论求解等效粘滞阻尼比，以近似描述非经典阻尼体系的阻尼耗能特性。考虑几何非线性及非经典阻尼因素，对一座双链式悬索桥进行了地震反应谱和时程反应分析。引入主缆形状系数，将单链式悬索桥作为双链式悬索桥的特例，就同跨度同矢高的双链式悬索桥和单链式（普通式）悬索桥地震反应进行对比分析，揭示双链式悬索桥地震反应特征。双链式悬索桥地震反应特征的研究对该类桥设计选型、动力性能评估及抗震加固设计都有重要的工程意义

Seismic response characteristics of double cables suspension bridge

Damping in double cables suspension bridge composed of steel reinforcement beams and reinforced concrete tower is non-classical,which leads to coupled equations of motion in main coordinate system.Based on the complex damping theory,the equivalent viscous damping ratio was derived,which can be used to describe energy dissipation characteristics of non-classical damping system approximately.The seismic response of double chains suspension bridge was analyzed through a pratical example,considering the geometric nonlinearity and non-classical damping,and numerical calculation was presented for seismic response of the bridge subjected to independent effect or combination effect of three orthogonal components of seismic wave respectively.Single cable suspension bridge can be taken as a special case of double cable suspension bridge,after the main cable shape coefficient was introduced.The dynamic responses of double cable suspension bridge and single cable suspension bridge were compared to reveal the ristics of seismic response of double cable suspension bridge.The study has a positive significance on structural form selection,dynamic performance evaluation and reinforcement design of such type of bridges.